Fluid flow control means



Jan- 5, 1960 A. SHERMAN ET A'. 2,919,543 FLUID FLOW CONTROL MEANS v Filed Aug. e, 1957 5 sheets-sheet 1 .37" 38 'L- V//l INVENTORS. Afef/faz WMA/AM neuer A Few: Alva 572425) .5: L ze Jan. 5, 1960 A. SHERMAN ETA'.. 2,919,543

FLUID FLow CONTROL MEANS med Aug. e, 1957 s sheets-sheet 2 Jan. 5, y1960 A. SHERMAN ETA'. 2,919,543

FLUID FLOW CONTROL MEANS Filed Aug. e; 1957 s sheets-sheet s 6 lll 442 45 II ll J7 36 l! u I l/l/l/ 3j y n E Ik *Er /l/ WL//l Jg 37 ,Q9 36 46 A rae/Vgn? FLUID FLOW CONTROL MEANS vArthur Sherman, West Caldwell, De Lacy F. Ferris,

Application August 6, 1957, serial No. 676,694

4 claims. (ci. so-ssn) y* This invention relates generally to improved control 'means for the supply of combustible liquids to combustion apparatus, and, as illustrated herein relates especially to jet propulsion apparatus of the type wherein a liquid fuel is used in combination with an oxidant such as liquid oxygen.

.l et propulsion motors have heretofore been operated by burning fuel in a combustion chamber and causing the ensuing products of combustion to be ejected through an exhaust nozzle to create the propulsive force. The amount of thrust produced in a jet propulsion motor is dependent on the mass of products o-f combustion ejected through this nozzle. in order to vary the stage of thrust produced, it is necessary to vary the amount of cornbustible fuel and oxidant arriving at the combustion chamber. An object, therefore, of our invention is to provide two or more stages of thrust in a jet propulsion ,apparatus by varying the amount` of combustible fuel and oxidant passing from the supply tanks to the combustion chamber.

With the foregoing and other objects and features in View, the invention will now be described with particular reference to the accompanying drawings in which:

Figure l is a schematic diagram illustrating the aplication of the mechanism of this invention to a rocket combustion chamber;

Figure 2 is an elevation view, partly in section, of the invention before operation;

Figure 3 is a View of the fuel cylinder in section when the mechanism is delivering a high stage of thrust;

Figure 4 is a view of the fuel cylinder in section when the mechanism is delivering a second lower degree of thrust; and

Figure 5 is a modification of the valve shown in Figure 3.

Referring first to Figure l, an explosive charge in the chamber 18 is ignited by an igniter 19, through a switch 20 and a suitable source 21 of electricity. Compressed inert gas, such as nitrogen, is stored in a tank 17 which pressurizes fuel tank 13 and oxidant tank 14, through an explosive operated valve 16 and conduits 15. Conduits 11, 12 supply oxidant and fuel, respectively, to the upstream ends of fuel cylinder 6 and oxidant cylinder 7. A conduit 9 supplies fuel from the upstream end of fuel cylinder 6 to the downstream end of actuating cylinder 8. Conduit 4 delivers fuel from the downstream end of fuel cylinder 6 to combustion chamber 1 lthrough injector 2. Conduit 5 delivers oxidant from the downstream end of oxidant cylinder 7 to combustion chamber 1 through injector 3.

Referring now to Figure 2, fuel enters fuel cylinder 6 through conduit 12 and goes through either high thrust exits 37 or low thrust exits 38 into the surrounding chamber 39, from whence it is conducted to the combustion chamber 1. A disc 41 supported by poppet 34 keeps the system hermetically sealed. The construction of oxidant cylinder 7 is similar to that of fuel cylinder 6, the oxidant 4NUnited States Patent() ,i ce

entering through conduit 11 and leaving through conduit 5.

The actuating cylinder 8 incloses a piston 31 and rod 31a moved in one direction by explosive gas pressure through conduit 10, and inlet 40 and in the other direction by fuel pressure through conduit 9 from fuel cylinder 6. A rod 31a is connected to a cross bar or yoke 32 which actuates rod 33 in the fuel cylinder 6 and a similar rod 33 in oxidant cylinder 7. In the fuel cylinder 6, the poppet 34 is moved toward the downstream end by a rod 33 and moved toward the upstream end by a return spring 36 abutted against the cylinder end closure 23. `The oxidant poppet is acted upon in the same manner.

Before operation, the mechanism of the invention will assume the position shown in Figure 2. *In operation, closing switch 20 will energize igniter 19 and simultaneously ignite the explosive charge in the chamber 18, thereupon opening valve 16 which releases 4inert gas under vhigh pressure from tank 17 in order to pressurize fuel downstream, the fuel pressure in line 12 and the oxidant pressure in line 11 rupture the now unsupported discs 41, thus allowing fuel and oxidant to enter cylinders 6 and 7.' The poppets 34 and actuating piston 31 continue to be displaced toward the right by the pressure of the explosive charge until they assume the position shown in Figure 3. With the mechanism in the position as shown in Figure 3, the fuel is free to enter fuel cylinder 6 through conduit 12 and to pass through the large exit ports 37 into chamber 39 and thence into conduit 4 which conducts fuel to injector 2 and combustion chamber 1. Likewise, oxidant may enter oxidant cylinder 7 through conduit 11 and exit through conduit 5 into injector 3 and combustion chamber 1. With the fuel and oxidant passing through the large ports 37, a great quantity of fuel and oxidant arrives at the combustion chamber 1, thus producing a high level of thrust.

As the explosive charge 18 burns itself out, the pressure through conduit 9 overcomes the waning explosive gas pressure, moving piston 31, crossbar or yoke 32 and rods 33 and 33' back to their original position as in Figure 2. The pressure drop across port 35 produces a force acting downstream which the return spring 36 counterbalances when a desired portion of the small ports 38 are uncovered. The mechanism now assumes a position as shown in Figure 4, wherein flow through ports 37 is stopped because of closure by piston 34. As fuel pressure decreases, the downstream force on the poppet also decreases. The return spring 36 will then cou-uterbalance poppets 34 at a position closer to the upstream end of the cylinders 6 and 7, thus uncovering a larger part of small ports 38 and maintaining a constant rate of flow of fuel and oxidant. With the fuel and oxidant passing through the small ports 38, a small quantity of fuel and oxidant arrives at the combustion chamber 1 thus producing a low level of thrust.

vIt is obvious that the lower level of thrust is dependent upon the position of the poppet 34 relative to the smaller fuel ports 38. This relative position may be changed by modifying the characteristics of the poppet return springs 36. The spring can be modified and can be used to provide two or more stages of thrust on the lower thrust level.

Vvreturn spring 36.

KIn operation, the poppet will be in the position shown in Figure 5. The lowest level of thrust is produced when the movable end closure 23 is resting against snap ring 24 thus giving minimum compression pressure to poppet Fluid underpressure is admitted to chamber 42 through conduit 43 and end cap 45 thus applying a force on the rear face of movable end closure 23 which displaces it toward the abutment 46 on cylinder 6. The pressure may be of such magnitude that the force on end closure 23 is greater than return spring 36 thereupon displacing end closure 23 to its extreme position against the abutment 46 on cylinder 6. This increases the compression pressure on poppet return spring 36, displacing poppet 34 toward its upstream end and uncovering a greater part of the low thrust ports 38 thus producing a greater rate of ow and hence greater level of thrust than in the previous position. By varying the pressure within chamber 4Z the position of end closure 23 may also be varied producing any level of low thrust with the latter two levels as extremes.

Although the present embodiment of the invention has been illustrated as applied to a jet propulsion motor, this in no way limits the scope of the invention as it may be adapted `to use in many other applications.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

1. A device for controlling the ow of at least two fluids comprising a container for each fluid, means for pressurizing said containers, valve means associated with each container for controlling iluid iiow, each of said valve means comprising a cylinder having an inlet connected with its associated container, said cylinder having at least one orifice for outlet flow of the fluid directed into the said cylinder, valve piston means mounted within said cylinder for movement from a closed position covering said inlet to an open position, means for biasing said valve 4 pistons toward closed position, control valve means comprising a cylinder and control piston, said cylinder of said control valve having a conduit connected between it and one of said cylinders of said valve means for transmitting fluid pressure to bias said control piston when said valve is open, pressure means connected with said cylinder of said control valve for causing movement of said control piston in a direction opposite to said bias, and means for connecting said control piston with said valve pistons for causing actuation thereof toward open position only when said pressure means actuates said control piston, said valve pistons having an orifice therein whereby the pressure differential between the inlet side of said valve piston and the biased outlet side controls movement of said piston to control iluid flow.

2. A device as defined in claim l for use with fuel and oxidant fluids including means connected with said valve piston biasing means for varying the iluid ow by varying the bias.

3. A device as deiined in claim l including a series of orifices for outlet flow, one of said orifices being in uid connection with its cylinder at initial operation of said valve piston when said pressure means for said control valve is in operation, and the remaining orifices being in uid connection with its cylinder only upon cessation of said pressure means for said control piston.

4. A device as defined in claim l including sealing means at said valve cylinder inlets supported by said valve pistons.

References Cited in the tile of this patent UNITED STATES PATENTS 2,402,826 Lubbock June 25, 1946 2,714,286 Zucrow Aug. 2, 1955 2,794,318 Zucrow et al. June 4, 1957 2,808,700 Kretschmer Oct. 8, 1957 

